For serious dehydration first recourse is an I.V. Pedialyte is an effective home treatment for moderate dehydration

Know your sweat rate.

This involves working out in a given temperature for a fixed amount of time and determining the rate at which you lose fluids. Powerbar.com has a simple calculator to assist you with this: http://www.powerbar.com/calculators/sweat.aspx

Heat acclimation training

The concept here is to regularly submit your body to training in the heat prior to an expected hot race. Research shows this can be an effective strategy. Training in heat increases blood plasma volume over time and promotes other positive physiological adaptations to exercising in the heat. It is not a “quick fix.” Training in the heat the week before a race won’t help. Adaptation occur over a 3-4 week time period. Sessions need not be longer than 100 minutes. Acclimation must be maintained otherwise the positive effects begin to diminish.

What is sun poisoning?

Not real poisoning. Just a severe sunburn.

Symptoms include: blisters, fever/chills, headache, nausea

Treatment: cool bath/shower, ibuprofen or acetaminophen for pain, aloe gel, increased fluid intake for a few days following.

What is heat stroke?

Heatstroke is a life-threatening condition that occurs when your body temperature reaches 104 F (40 C) or higher. Heatstroke can be brought on by high environmental temperatures, by strenuous physical activity or by other conditions that raise your body temperature.